1. Field of the Invention
The present invention relates to a hinge construction for the effectuation or hingedly articulated connection between a lid and an aperture which is located on a plate member, and more particularly, provides for a hinge structure which facilitates a spring-biased floating sealing connection between the lid and a surface about the aperture ion the plate member, which may be a component of a mechanically interlocked switch box cover, adapted to impart a uniform sealing pressure to a gasket interposed between structure mounting the lid on the hinge and the surface about the aperture.
2. Discussion of the Prior Art
In general, hinge constructions of the type considered therein, which are frequently employed in connection with so,called mechanically interlocked switch box covers, incorporate a hinge arrangement possessing a disc-like portion having a cup-shaped closure lid mounted thereon for rotation relative thereto, with the lid having latching elements provided about the free edge of the cup flange portion thereof adapted to engage cooperating latching elements on a raised surface extending about the aperture in the plate member responsive to relative rotation between the closure lid and the aperture, so as to seal the aperture.
The hinge construction, as is well known in the art, essentially includes a depending flange or hinge arm portion projecting downwardly from an edge of the disc portion of the hinge mounting the lid, and extending generally perpendicular thereto; which hinge arm portion at its distal free end is provided with a through hole adapted to receive therein a hinge pin extending through two therewith aligned hinge ears or hinge mounts on the plate member at opposite sides of the flange or hinge arm portion of the hinge structure. A helical spring member may extend about the hinge pin within the aperture so as to impart suitable torsional biasing action to the lid when the latter is latched with the cooperating latching means on the surface structure about the aperture on the plate member, so as to cause a sealing pressure to be imparted to a gasket interposed between the lid-supporting hinge structure and the aperture in the plate member.
Although the foregoing arrangement enables appropriate sealing to be effected between such hinge-mounted lids and plate members, the latter of which may be a constituent of a switch box cover or the like, frequently the utilization of a normally circular or round hole for the hinge pin in the hinge arm does not enable the imposition of a uniform sealing pressure along the perimeter of the annular sealing gasket which is interposed between the lower surface of the lid-supporting hinge disc member and the therewith contacting surface about the aperture in the plate member. This, at times, will either lead to excessive wear or a non-uniform compressive deformation of the sealing gasket, potentially preventing appropriate sealing to be implemented between the component which may enable the ingress of moisture and/or other foreign materials into the switch box.